Task 3- Risk factors for the development of breast cancer

Epidemiology of mammary gland CA

Worldwide:

*With 1 million new cases each year worldwide, breast cancer is the most common malignancy in women and accounts for 18% of all cancers in women.

*In the United Kingdom, which has the highest age-standardized morbidity and mortality rates in the world, the disease is the leading cause of death among women aged 40 to 50, with an incidence of almost per 1,000 women per year in women in their 50s.

 *Breast cancer in men accounts for 1% of cases worldwide.

At the national level:

1. In women: breast cancer is the most common form of cancer in Colombian women, representing about 16% of all cases of cancer diagnosed in women in Colombia, being women over 50 years of age.

In men: breast cancer in men is rare compared to women, representing about 1% of all cases of breast cancer and occurs in any male age.

2.In the areas of Colombia where breast cancer is most prevalent is in the Andean region (Bogota, Medellin, Cali) and in the Caribbean region due to multiple factors such as lifestyle, access to health services, genetic factors, dietary habits, economic factors, knowledge about the disease.

3. What factors do Colombians have to develop this disease?

 Specific risk factors for men: family history of breast cancer, hereditary genetic disorders, estrogen exposure, liver diseases.

 Specific risk factors for women: exposure to radiation at an early age, use of hormonal contraceptives.

Breast cancer

Cell cycle:

The process by which normal cells become cancerous is called carcinogenesis.

Cancer can be caused by changes in DNA that turn on oncogenes or turn off tumor suppressor genes. Changes in many different genes are usually necessary for breast cancer to arise.

For these tumor-initiating or tumor-promoting mutations to persist in a cell and give rise to a tumor clone, two fundamental events, which are common to all tumor types, must occur at the level of the cell and its microenvironment:

genomic instability that favors the acquisition of mutations and tumorigenic inflammation. the BRCA genes (BRCA1 and BRCA2) are tumor suppressor genes. When one of these genes changes, it no longer suppresses abnormal cell growth, and cancer is more likely to develop.

Cancer cells acquire the ability to migrate to other parts of the body, a process called metastasis, and to promote the growth of new blood vessels, a process called angiogenesis (which gives tumor cells a source of oxygen and nutrients). Cancer cells also do not undergo programmed cell death, or apoptosis, under the conditions that normal cells would (e.g., due to DNA damage).

In normal cells there are several mechanisms that control the accumulation of spontaneously occurring mutations: cell cycle arrest, DNA repair, and the eventual destruction of a badly damaged cell by apoptosis.  Apoptosis is the physiological form of cell suicide involved in embryogenesis, tissue cell turnover and the elimination of infected, mutated or damaged cells.

Tumor markers:

The most commonly used markers in breast cancer are CA 15-3 and carcinoembryonic antigen (CEA), which are not currently recommended as markers for breast cancer screening or diagnosis.

For breast cancer, CEA has been associated with disease extent and prognosis.

CA 15-3 is a polymorphic epithelial mucin-related (derived) antigen, a marker for breast cancer. Levels higher than 30 U/mL CA 15-3 are linked to lower overall survival, but are unrelated to tumor size, nodal status and age.

Classification of breast cancer:

Luminal A, 

luminal B (can be HER2 negative or HER2 positive), HER2 and basal like.

Luminal tumors have positive hormone receptors, HER2 expression and basal like or triple negative tumors express neither hormone receptors nor HER2.

Luminal A subtype has the best prognosis and basal like has the worst prognosis.

PHYSIOPATHOLOGY OF BREAST CANCER:

Breast cancer consists of the accelerated and uncontrolled proliferation of cells of the glandular epithelium. These are cells that have greatly increased their reproductive capacity...

Breast cancer cells can spread through the blood or lymphatic vessels and reach other parts of the body. There they can attach to tissues and grow to form metastases.

It has been shown that constant exposure to estrogens generates these mutations and that overexposure to lithium associated with obesity in mammary adipose tissue causes an increase in cell purification and, in turn, cancer formation.

Other associated mutations are those in the guardian of the genome p 53 and the gene associated with breast cancer (BRCA1 and BRCA2) which cause uncontrolled cell division, inhibition of apoptosis and metastasis to distant organs.

CHANGES THAT OCCUR IN THE BREAST:

A lump in the breast or in the armpit (under the arm).

Changes in the shape of the breast, if the breast appears swollen or an area of skin retraction appears.

Nipple retraction and eczema.

Discharge of blood from the nipple.

If you feel pain in the breast, it is likely to be a benign lesion, but it can also be breast cancer.

Changes in the skin of the breast, which resembles the rind of the orange (orange peel).

Benign diseases

Benign (non-cancerous) breast conditions are unusual growths or other changes in the breast.

 are unusual growths or other changes that occur that occur in the breast tissue and are not cancer.

Signs and symptoms of benign breast conditions:

There are many different types of benign breast conditions, but they all cause unusual changes in the breast tissue. Sometimes they affect the glandular tissue (the system of lobules and ducts that produce milk and transport it to the nipple).

Some Benign Conditions: 

• Radiological image of mastitis:

• Mammary duct ectasia:

• Skin-associated infections:

Bibliography 

McPherson, K., Steel, C. M., & Dixon, J. M. (2000). Breast cancer-epidemiology, risk factors, and genetics. BMJ : British Medical Journal, 321(7261), 624-628. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1118507/

 

Sánchez Basurto, C. (2010). Treatise on diseases of the mammary gland. Editorial Alfil, S. A. de C. V. UNAD.